* {
  margin: 0;
  padding: 0;
}

html,body,#app {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

#app {
  display: flex;
  flex-direction: column;
  header, footer {
    height: 36px;
    background: skyblue;
  
  }

  main {
    flex: 1;
    overflow-y: scroll;
    .title {
      b {
        &.active {
          color: red
        }
      }
    }
    .con {
      >div{
        display: none;
        &.active {
          display: block;
        }
      }
    }
  }
}

